.NET: Update to the lates MCP nuget

[SergeyMenshykh]

The Agent_MCP_Server_Auth sample fails with the error:

ModelContextProtocol.McpException Message=Failed to handle unauthorized response with 'Bearer' scheme. The AuthorizationRedirectDelegate returned a null or empty authorization code.

This is caused by the trailing slash in the resource segment of the authorization URL: resource=http://localhost:7071/.

The same issue (modelcontextprotocol/csharp-sdk#1122) in the MCP repo has been recently fixed, but the fix has not been released yet. Update AF to the latest (>0.8.0-preview.1) MCP package when it is released.

[neerajkaram]

Happy to take this one. Planning to bump ModelContextProtocol to 1.2.0 in Directory.Packages.props and drop the now-redundant VersionOverride="1.2.0" in HostedMcpTools.csproj, picking up the trailing-slash fix from modelcontextprotocol/csharp-sdk#1264. Built locally against Agent_MCP_Server_Auth, restore and build both clean. Will open a PR shortly.